The C8 that thinks it's a SRK


I actually still dont know for sure. Even after all of the testing, removing of the parts, checking for shorts, putting parts back on I still wasn't able to find the problem. I couldnt find a short or any ringer that didnt mirror a stock board.

Finally I decided to try again with a new board and new zener and just like magic I got light.

Even thought I wasnt able to salvage the first driver I dont even care. I am just happy I will be able to deliver product to the customer as promised.

Things would not have turned out that way if you and RMM had not chimed in. After having tried every thing I knew to try my only recourse would have been to use a buck driver instead, or assume I had been shipped mislabeled parts and try ordering again. Sometime a second set of eyes and a little encouragement is is the most effective tool used in this hobby.

Thanks again.

Glad it ended well! I have been similarly frustrated many times.

……I won’t have any stock C8s or C12’s left in a few weeks.

And a special howdy to vestureofblood too!

Nice! Man what a powerhouse...silly question, but how hot does that thing get before it get's too hot

Also I recommend you building one of the Tivo East-092 (7135's up to 1400mA, then "turbo" FET up to like 12A! [might want to put a timeout of 60-90 seconds on turbo because with that much juice, your batteries might not make it!]

But I believe is also a 17mm ATtiny driven driver in the works that is fixing to make an even BIGGER powerhouse ;)

Awesome build though!

In order to do the zener mod do I need to change the value of either component if I wanted to use a higher voltage LED set up? Say for example 3 leds and 3 li-ion cells or 4,5 etc?

I've done 3S (approx. 12 volt) input without any changes, I think that 4S would also be fine given the low amount of heat dissipated by the zener diode. That said, you need to make sure that you aren't exceeding the ratings of the 7135s, MOSFETs, or other components. I don't think the 7135s will be happy with more than 2S.

The power-handling side of the 7135 or FET only sees the difference between Vin and Vf, neither one ever sees the full input voltage. The voltage applied to the gate (FET) or Vdd (7135) pins is supplied by the MCU, and the MCU can't put out a higher voltage than what goes in, so if the zener limits the MCU voltage to 4v the voltage at the gate/Vdd will be 4v as well.

These FETs are what's called 'logic-level gates', meaning 0-5v. They're specifically built to use a low level/low power signal direct from a microcontroller without any other components in the chain.

I get that and my statement is consistent with what you're saying, I understand how 7135s work and what the zener mod does. I said what I said so that others with less experience would understand that you can't just zener mod the MCU then go on your merry way running whatever cells behind it you'd like, there are other components to consider as well.

You know that the amount of heat dissipated will go up A LOT in the 7135s trying to regulate anything at 3S. The 7135s are already on fire regulating an MT-G2 with fresh cells. Sure, if there is no regulation going on then they won't generate much heat, but then what would be the point of using 7135s?

You need you some of those Purple Efest 18350’s 10.5A that HKJ reviewed :smiley:

Only problem is…they are only like 800mAh…so that means…your run time will be short…bright…but short

Kind of like the Hayabusa…tires are rated to last for like 10 min at wide open throttle…gas tank only lasts 7 :smiley:

What do you think I've been running in mine lately? ;) They're only 700mAh though, the original Efest IMRs are 800mAh. They'll do about 9.5A direct drive into an MT-G2...for a few seconds at least. They are a huge step up in maximum output but they are much less efficient to use in a 7135 zener mod MT-G2 because they don't sag down nearly as much which ends up wasting a TON more heat in the 7135s.

The original Efest 18350s are just about right for use at 4.5A-5A in an MT-G2 mod with just enough voltage overhead to maintain regulation for a while but not enough to waste a ton as heat.

awesome! :smiley:

Sorry to bring this back from the dead, but I must say the tint and output is just beautiful!

Where’s Comfy at?

Does widening the base of the reflector and adding the white plastic piece add to lumens or throw? I had thought the white piece was just for centering the LED. If a wider base adds to throw I have some work to do on my lights..

… throw is a matter of surface brightness, focus, and the efficiency of your optical system (lenses, windows, reflectors, etc)… and nothing else.

See here:
DrJones - Flashlight Optics - Dome, Dedoming and Throw

This! I hope he is ok.

I have double checks the charts and as far as I can see the 5000k 3B is the closest bin to the P0. waiting on the new q0 to see how it is different.

Is it possible that we are in need of a new workhourse MCU if the 7135 is running so hard trying to run emitters now with twice the voltage?

Remimber that part of the point is to minamize the amount of heat (because it is just waste). If we spec a different component could it more efficently? If so then it is a bonus all around.

Ok the 7135’s may not be happy being out of work, but they get tortured around here anyway.

It seems to me that 3s 18650’s is a great energy source for the new 6v emitters. Now what does it take too run them with out making hand heaters (other emitter heat) which we can control via amperage and by design.

I am asking a question no giving an answer.

I don’t have 3B tint light but I compared 3C to my MT-G2 P0, the latter is whiter and cleaner while 3C have yellow with a hint of green when you directly compare the two. Keep in mind reflector play a huge role in the light rendition.

Keep reading. The answer to your question is keep reading. A 7135 is certainly not an MCU. (If someone asked me what it was I’d call it a monolithic linear current regulator. Here is a datasheet for you to learn a little from - )

I don’t mean to be standoffish, but I really doubt that this thread is the place to ask questions about drivers.